Help:: Howto print a receipt from xul?

I have a custom xul application running in mozilla.  After the user has
entered some information, I need to print that information.  How do I do
this?

Also, I don't want any screen to pop up.  Once the user finishes entering
the information, I show him a screen saying please take your receipt. I want
the receipt to be printed on the load of that xul window. Essentially

<window 
  id="takeReceipt" 
  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
  onload="printReceipt()"
>


Do I use xpcom?  Can javascript alone do this?

Thanks for the help.

- David
-- 
A wise man once said: If it didn't come with source, it's firmware not software.

David W. Bourgoyne
[email protected]